Apparatus for producing needled batts



Sept. 8, 1959 A. w. BATEMAN APPARATUS FOR PRODUCING NEEDLED BATTS FiledOct. 10, 1956 2 Sheets-Sheet 1 INVENTOR ALVA WAYNE BATEMAN Sept. 8, 1959A. w. BATEMAN 2,902,746

I APPARATUS FOR PRODUCING NEEDLED BATTS Filed Oct. 10, 1956 2Sheets-Sheet 2 BY W AGENT United States Patent 2,902,746 I APPARATUS FORPRODUCING NEEDLEDBATTS Alva Wayne Bateman, Newburgh, N-Y., assignor toI. du Pont de Nemours and Company, Wilmington, Del., a corporationof'Delaware Application October 10, 1956, Serial Nor 615,041 1 Claim.(c1. 28-4) This invention relates to unwoven fibrous materials and moreparticularly to'a'n' improved apparatus and process for needle punchingunwoven fibrous batts, especially thin batts of slippery fibers.-

Needle looms have been used by the textile industry for many years inmaking punched felts from batts of carded or similarly oriented fiberssuch as hair, jute,- sisal and other natural fibers; These punched feltshave been used, for example, as carpet linings, insulating felts,slicker felts and cartridge wadding. Recently, needle looms havebeenused similarly in-making unwoven batts of synthetic fibers.

Basically, these needle looms consist: of a large number of closelyspaced needles s upportedvin position to be reciprocated into then outof a batt of fibers and means, such as draw rolls and moving feedaprons, to pass the batt through the loom. The batt is usually movedintermittently through the loom, being advanced only while the needlesare drawn clear of the batt. This needle piercing or punching orientsindividual or small groups of fibers substantially perpendicular to theplane of the batt, thereby giving added strength to the unwovenstructure.

Although they have been satisfactory for punching batts of many naturalfibers, conventional needle looms greatly distort batts of syntheticfibers which have a low coefficient of friction and slide easily overone another. This is especially true of thin batts of such materials aspolytetrafluoroethylene which stretch and pull apart on conventionallooms. With some thin batts, for example, those less than A inch thick,the unwoven fibrous structure distorts when it is suspended under itsown weight over a short distance.

I have discovered an improvement in conventional needle looms whichmakes it possible to use such looms for punching thin batts of slipperyfibers without greatly distorting the batts. This improvement comprisesan endless flexible carrier belt for the fibrous batts which runs fromthe feed side of the needle loom to a point immediately adjacent to thepunching area, passes outside the punching area to a point immediatelyadjacent to the discharge side of the punching area, and proceeds awayfrom the loom.

The invention is described in detail hereinafter by reference to apreferred embodiment shown in the accompanying drawings wherein:

Figure l is a view in side elevation of the needle loom and carrier,

Figure 2 is a plan view of the needle loom and carrier,

Figure 3 is an enlarged cross-section of the bridge plates and punchingarea shown in Figure 1.

As shown in the drawings, the loom needles are held in the needle board11 which, in turn, is fastened to the top beam 12. The needle assemblyconsisting of the needles 10, needle board 11 and top beam 12 isreciprocated substantially vertically between top-beam guides 13 byconnecting rods 14 which are connected to drive shaft 15 througheccentric straps 18 and eccentrics 2 19. As the drive shaft 15 is turnedby a prime mover through pulley- 16 and clutch 17, 'eccentrics' 19rotatewithin the eccentric straps 18 which move the connecting rods 14 and theneedle assembly. As the needles 10 reciprocate, theypass downwardlythrough holes'in the stationary stripper plate 20, through the punchingvarea I and finally through corresponding" holes in the; stationary bedplate 21. Figure L shows the position of the needles 10 as they begintheir-downward stroke' Figure' il shows the needles after they havepassed through stripper plate 20, the punching area andbe'd-plate 21.

In Figure 1, feed crank 22, fastened to eccentric 19, is rotatablyconnected to clutch lever ".23 which is also rotatably connected toclutch pitman 24 7 When the drive shaft 15 and eccentric 19' turn,clutch lever 23 causes clutch pitman 24 to oscillateback and forth.Ratchet 25 attached to clutch pitmanl 24 engages gear 26 and intermittently rotates rear 'dr'aw'roll 27. The rear draw'roll 27intermittently rotates forward draw roll 28 through chain drive 29; Theslatted'feed apron 30is driven intermittently by frictional contact-Withforward draw roll 28. Thus' the needle assembly, the -feed-mechanism andthe rear draw roll 27 are all driven-from eccentric 19.

The'endless fl'exible' carrier: 31 runs along the top-surface of theslatted feed apron 30- up :to a point immediately. adjacent-tothe-punching area. .FOI'WEIIds. bridge plate 32 is inserted inthespacebetweenathe -feed end 1 ofbed plate 211and-;draw-roll 28' sotthat' thecarrier'31 is supported between thefeed-apron 30 and the bed'plate 21.From the feed apron 30, the carrier 31 passes over the bridge plate 32and downwardly through the small space between the bridge plate 32 andthe bed plate 21. The carrier then runs around lower girts 33, thusavoiding drive shaft 15, and passes upwardly through the slit betweenthe discharge end of bed plate 21 and a second bridge plate 34 which,like forward bridge plate 32, spans the gap between the bed plate 21 andthe rear draw roll 27.

From this point immediately adjacent to the discharge side of thepunching area, the carrier 31 goes successively between draw roll 27 andriding roll 35, under windup roll 36, over roll 37, under roll 38 andaround pull roll 39 and guide roll 40 back to roll 41 at the end of theslatted feed apron 30. Roll 38 controls the tension in the carrier 31;by lowering this roll the tension is increased. Means are provided tosynchronize the intermittent rotation of windup roll 36 and pull roll39, with that of draw rolls 27 and 28.

The carrier 31 is driven by frictional contact with rear draw roll 27and pull roll 39. The carrier 31 can be made of any of a wide variety offabrics and sheetings, natural or synthetic, that is flexible enough tobe threaded through the loom; however, coated fibrous sheets andpolymeric films, for example, drill lightly coated with plasticizedpolyvinyl chloride and polyester film such as 350-A gauge polyethyleneterephthalate sheeting, are preferred.

In operation, a loose unwoven batt 42 of fibers to be needle punched islaid on the carrier 31 on the feed apron 30 and is borne up to bed plate21. As the batt 42 passes into the punching area between bed plate 21and stripper plate 20, it is punched by the reciprocating needles 10which orient small groups of fibers substantially perpendicular to theplane of the batt. Stationary plates 20 and 21 limit the verticlemovements of batt 42 while it is punched and prevent it fromreciprocating unduly with the needles. When the punched batt 42 haspassed through the loom it again meets the carrier 31 where the carriercomes upwardly between the discharge end of the bed plate 21 and thebridge plate 34. From this point immediately adjacent to the dischargeutility of the invention and is not intended to limit the inventioninany Way. 4

Example j Aloose batt of 4 /-inch, '6%-denier polytetrafluoroethylenefibers drawn t'entimes their extruded length was formed by cross-lappingfrom 13 to 15 layers of loose fibers. Thelo'osebatt was then fed to aneedle loom equipped with a carrier of drill lightly coated withpolyvinyl chloride. The carrier was. threaded over the bridge plates andthrough the loom fas shown in Figures 1, 2, and 3. The loom needles were15 x 18 x 36 gauge, 3 /2 inches long, and close barbed andshallowbarbed. I 'In 18 passes through the loom, the batt was punched 3868times per square inch; The resulting product Weighted 17.6 ounces persquare yard and was i -inch thick. During the needle punching the. battstretched less than 15% in length and shrunk less than, 10% in width;similar battsof polytetrafiuoroethylene distort as I claim:

In a needle loom for punching unwoven fibrous batts which loom comprisesa plurality of closely spaced needles, means to reciprocate said needlesinto and out of said batts, means for limiting the vertical movement ofsaid batts as said needles pass therethrough, a feed apron, means tomove said batts away from said loom comprising a draw roll, and a winduproll, the improvement which comprises a first bridge plate extendingfrom the discharge end of said feed apron to a point on the feed side ofsaid loom immediately adjacent to the area wherein said needles punchsaid batts, a second bridge plateextending from a point on the dischargeside of said loom immediately adjacent to said area wherein said needlespunch said batts to said draw roll, an endless, flexible carrier beltwhich runs along and in contact with the upper side of said feed apron,over the upper surface of said first bridge plate, downwardly over theedge of said first bridge plate immediately adjacent to said area wheresaid needles punch said batts, outside said needles and said limitingmeans, upwardly over the edge of said second bridge plate immediatelyadjacent to said area wherein said needles punch said batts, over theupper surface of said second bridgeplate and over said draw roll to saidwindup roll, and means to control the tension in said endless,flexiblecarrier belt. 1

References Cited in the file of this patent UNITED STATES PATENTS Shaw-4; Jan. 17, 1956

